lab 6

Lab 6: Phyla Porifera, Cnidaria, and Lophotrochozoans

• The lab covers material from Chapters 28 and 29.
• The formal report due date has been extended to March 14 at midnight.
• The report must be submitted as a single PDF to the assignment folder on D2L.
• Data for the report has been posted on D2L.
• Ensure the data used is specific to a particular lab section.

Nutrient Experiment

• The report investigations connect to how plants react to 3 macronutrients: N, P, and K.
• Questions for lab report:
• Why are nitrogen, phosphorus, and potassium important?
• Why was barley chosen as a study organism?
• Comparison of how plant organs responded to nutrient deficiencies.
• comparison of results to barley experiments in published scientific papers with similar setups.
• Use remaining lab time to analyze data.
• The results section is written in past tense.
• The first sentence of results should state the most significant findings
• Figures summarize findings, not raw data, with numbered captions.
• Graphs should be easy to interpret

Kingdom Animalia

• Organisms in this kingdom are multicellular with complex tissue types.
• They are eukaryotic and heterotrophic.
• They lack cell walls.
• Sexual reproduction is the main reproductive method
• The diploid stage is dominant, known as the diplontic life cycle.

Triploblastic Animal Body Plans

• Ectoderm: Outer layer developing into the nervous system and epidermis.
• Mesoderm: Middle layer differentiating into muscle cells and connective tissue.
• Endoderm: Innermost layer forming the internal organs.
• Acoelomates: Lack a body cavity.
• Pseudocoelomates: Have a body cavity that is not completely lined by mesoderm.
• Eucoelomates: Possess a true coelom, a body cavity completely lined by mesoderm.

Body Symmetry

• Body symmetry differs between quadrupeds and bipeds with different planes of reference
• Some of the planes discussed are Sagittal, Transverse and Frontal planes

Phylum Porifera (Sponges)

• Lack true organs, tissues, and systems.
• They process on a cellular level.
• Sponges have specialized cells, motile larvae, are eukaryotes and heterotrophs, and lack cell walls

Porifera Anatomy

• Osculum: Opening where filtered water is expelled.
• Spongocoel: Hollow inner space lined with choanocytes.
• Choanocytes: Flagellated cells that filter water for nutrients and create a current.
• Ostia: Incurrent canals lined with choanocytes.

Porifera Body Plans

• Three basic body plans: ascon, sycon, and leucon.

Sponge Diversity (Lab Activity)

• Three examples of sponges for observation: a Venus flower basket, a bath sponge (Spongilla sp.), and Scypha (Granita) (microscope needed).
• Key concept for the lab exam: distinctive characteristics of the phylum Porifera, but knowledge of specific scientific names or classes is not necessary.

Phylum Cnidaria

• Diploblastic containing two germ layers: gastroderm and ectoderm.
• Features an incomplete digestive tract, where food is ingested and wastes are expelled through the same opening.
• Cnidarians have radial symmetry and nerve nets for movement.
• They are dimorphic, existing in two body forms.
• Cnidocytes are stinging cells

Cnidaria Diversity - Hydrozoa

• Polyp form is dominant.
• Undergo dimorphic life cycle: asexual reproduction in polyp form and sexual reproduction in the medusa form.
• Individuals can be solitary or colonial; an example of the class is Portuguese man o' war

Cnidaria Diversity - Scyphozoa (True Jellyfishes)

• "Scyphozoa" means "drinking cup."
• Medusa stage is dominant.
• Polyp stage is reduced or absent.
• Oral arms and cnidocytes are used for both defence and to paralyze prey
• Gonads are the sex organs.
• Subgenital pits provide oxygen to gametes.

Spotlight Organism: Aurelia spp.

• A ring and radial canal are ciliated.

Cnidaria Diversity - Anthozoa (Flower Animals)

• Polyps only.
• Colonial or solitary marine organisms with sexual and/or asexual reproduction.
• Includes sea anemones, sea fans, and corals.

Spotlight Organism: Metridium sp.

• Sea anemones found in cooler waters of northern pacific and Atlantic oceans

Phylum Platyhelminthes (Flatworms)

• They are dorsally flattened.
• There is bilateral symmetry with cephalization.
• They are acoelomate.
• They are monoecious.
• Their digestive system is incomplete
• There are no respiratory or circulatory systems
• They have flame cells

Platyhelminthes Diversity

• Example Classes: Turbellaria (Planaria), Trematoda (parasitic flukes), and Cestoda (tapeworms).

Focus on life history traits for memorization.

• Focus on understanding the differences between the classes based on their life history traits.
• Unique features to the class Cestoda due to parasitic lifestyle should be noted

Spotlight Organism: Dugesia sp. (Planaria)

• Free-living flatworms

Phylum Mollusca

• Molluscs have four main morphological features: a protective shell (sometimes reduced), a mantle, a visceral mass, and a foot.

Mollusca Diversity

• Classes include Gastropoda (snails, slugs), Bivalvia (mussels, clams, scallops), and Cephalopoda (octopuses, squid).
• Focus on comparing what makes the shells of each class different and match them to the correct class.

Phylum Annelida

• These organisms are coelomate.
• They have a complete digestive system.
• Their body is divided into segments called metameres
• This allows for specialization of body parts, and the segmentation helps locomotion
• Closed circulatory system
• A nervous system including well developed dorsal brain and ventral nerve cord.

Spotlight Organism: Earthworm (Lumbricus terrestris)

• Random draw earthworm dissection lab assignment

Earthworm External Anatomy

• Key external features include the mouth, segments, seminal groove, clitellum, and anus.

Earthworm Internal Anatomy

• Key internal anatomical features include the pharynx, esophagus, crop, gizzard, intestine, aortic arches (hearts), seminal vesicles, seminal receptacles, nephridia, septa, and cerebral ganglia.

Lab Safety and Clean Up

• Use scissors as the primary dissection tool, and use scalpels with caution.
• Avoid excessive force when cutting.
• Do not cut towards hand.
• Only one person should be dissecting at a time.
• Dispose of broken scalpels properly.
• Dissections go in the garbage.
• Clean dissecting trays, tools and stations before leaving.
• Clean all tools and leave beside the sink
• Do not discard pins
• Return lab coat is applicable

Class To-Do List

Chapter 28: Sea Creatures

• Phylum Porifera:
• observe sponge diversity
• Chack understadning question 1.1-1.3
• Phylum Cnidaria: -Observe Cnidaria diversity
  • Hydrozoa ex. Portuguese man-of-war
  • Scyphozoa ex. Aurelia (Label display model)
  • Anthozoa ex. Metridium (Label display dissection)

Chapter 29: Lophotrochozoans

• Phylum Platyhelminthes:
  • Diversity of Platyhelminthes classes Turbellaria, Cestoda and Trematoda
    • Label Dugseia sp.
  • Check understanding questions 1.1 to 1.6 -Phylum Mollusca
  • Diveersity of Mollusca classes gastropoda, cephalopoda and Bivalvia
    • Match the shell to correct class
    • Check Understanding, Questions 3.1-3.4
• Exercise 29.4 Phylum Annelida
  • Earthworm dissection 1-6 (Supplementary DISSECTION MATERIAL IN APPENDIX)
• Chap review questions -#1 (no rotifera) 2-4 8 10

Learning Objectives

Chapter 28- Understanding Creatures from the Sea

-Phylum Porifera -Identify the germ layers and the 3 distinct arrangements in triploblastic animals -Define protostomes vs. deuterostomes and give examples. -Understand the distinctive features of the phylum -Know 3 major body plans -Classify demo organisms organisms

• Phylum Cnidaria -Know distinct features of phylum Cnidaria and examples -Know the 4 classes and characteristics of each: Anthozoa, Hydrozoa, and scyphozoa
  • What phylum demo organisms belong to and why -Label structures of sea anemone and Aurelia from demo dissection

Chapter 29- Understanding the Lophotrochozoans

-What are lophotrochozoans? Two key traits? What are the four main phyla?

• Phylum Platyhelminthes -Know the distinct features of phylum Platyhelminthes -Know 3 classes and characteristics of each: Turbellaria, Cestoda, Trematoda. Life traits unique to each class -What phylum and class slides and demo organisms belong to

• Phylum Mollusca -Know key characteristics of phylum Mollusca

• Know the 3 classes and characteristics of each: Gastropoda, Bivalvia, Cephalopoda (Match the shells) -What phylum and class slides and demo organisms belong to

• Phylum Annelida -Know distinct features of phylum Mollusca -External and internal anatomy of earthworm

Protostomes vs. Deuterostomes

• Protostomes and deuterostomes categorized by their embryonic development.
• In protostomes, the first opening of the embryo becomes the mouth
• In deuterostomes, the first opening becomes the anus, the mouth opening develops later.

Cnidaria Body Forms

• Cnidarians in two versions: polyp and medusa. The condition of having two body forms is known as Dimorphism

Cnidaria Subclasses

• Hydrozoa- Both solitary and colonial forms. Dimorphic with polyp and medusa stages. Asexual reproduction in polyp and sexual in medusa stage

• Scyphozoa- The “true jellyfishes." Dominance of the medusa stage and reduction of polop stage. The jellyfish Aurelia for instance

• Cubozoa Box-shaped body and complex eyes

• Anthozoa Flower animals such as the sea anemone of genus Metridium